OMIM ID:
Fibrosis of Extraocular Muscles, CFEOM5
Alternate Names
Defective Genes
Clinical Characteristics
Ocular Features
This type of congenital fibrosis of extraocular muscles is sometimes called a congenital cranial dysinnervation disorder. Ptosis is of congenital onset while the nature of the strabismus is variable but bilateral. One sib with this disorder had Duane retraction syndrome.
Systemic Features
No systemic features have been reported.
Genetics
Inheritance
Homozygosity or compound heterozygosity of mutations in the COL25A1 gene is responsible for this autosomal recessive condition.
Other nonsyndromal forms of congenital fibrosis of extraocular muscles include: CFEOM1 (135700), CFEOM2 (602078), CFEOM3C (609384), and CFEOM with synergistic divergence (609612). See also Tukel CFEOM syndrome (609428).
Pedigree
Autosomal recessive
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.